Lifting platform

ABSTRACT

A truck, having an enclosed van including a door for access, has a hydraulically operated first platform mounted adjacent the side of the van by the door opening. The platform includes a pair of guide members slidably mounted to guide supports on either side of the door. A pair of hydraulic cylinders mounted on either side of the door opening have lifting rods actuated by the hydraulic cylinders and coupled to the platform such that the platform can be raised or lowered from the ground level to the floor level of the van. The first platform includes a hinged second platform which in a loading position is generally horizontal for receiving and discharging goods and when in a retracted position is vertically oriented and locked into position by locking means. The system is relatively inexpensive and can be easily removed from one truck and mounted to another truck.

United States Patent [1 Bryan LIFTING PLATFORM [75] Inventor: Carl E.Bryan, Grand Rapids, Mich.

[73] Assignee: Grocers Baking Company, Grand Rapids, Mich.

[22] Filed: Aug. 2, 1971 [21] Appl. No.: 167,972

Primary Examiner-Gerald M. Forlcnzu Assistant ExaminerLawrence J OreskyAttorney-Price, l-leneveld, l-luizenga & Cooper [57] ABSTRACT A truck,having an enclosed van including a door for access, has a hydraulicallyoperated first platform mounted adjacent the side of the van by the dooropening. The platform includes a pair of guide members slidably mountedto guide supports on either side of the door. A pair of hydrauliccylinders mounted on either side of the door opening have lifting rodsactuated by the hydraulic cylinders and coupled to the platform suchthat the platform can be raised or lowered from the ground level to thefloor level of the van. The first platform includes a hinged secondplatform which in a loading position is generally horizontal forreceiving and discharging goods and when in a retracted position isvertically oriented and locked into position by locking means. Thesystem is relatively inexpensive and can be easily removed from onetruck and mounted to another truck.

12 Claims, 4 Drawing Figures PATENTEBUEC 4 I975 SHEEI 10F INVENTOR. 562/941 BYQ PATENTEU DEB 41975 SHEET 2 OF 2 INVENTOR. 6 124 5. EEVIQU vBY' LIFTING PLATFORM BACKGROUND OF THE INVENTION The present inventionrelates to hydraulically operated lift platforms adapted to be used witha relatively small van-type of truck.

In many delivery truck operations, it is desirable to have an automaticlifting platform attached to the van of the truck for aiding thedriver-delivery man in the frequent loading and unloading of heavy loadsinto and out of the truck. It has been impracticable however, to supplysmall delivery trucks with a permanent factory installed hydraulic liftand platform mechanism since it would greatly increase the cost of thetruck as it is not a standard item that most buyers require. Thus, thedriver-delivery man of relatively small trucks must manually liftpackages, goods, or the like from the truck to the ground level and viceversa or from a loading platform into the truck and vice versa. In somecases, he can carry a hydraulically operated dolly which, of course,must be lifted into and out of the truck. With either method, the driveris faced with heavy lifting when the truck is used for carryingrelatively heavy packages.

SUMMARY OF THE INVENTION The lift arrangement of the present inventionprovides a relatively inexpensive add-on feature for a delivery truckwhich can be installed with relative ease and which can be removed fromone truck to another as one truck is sold or no longer requires thelift. When used with a truck having a rear door, the lift platform ofthe present invention forms an integral part of the rear bumper when theloading platform is in its stored or traveling position.

It is an object, therefore, of the present invention to provide aninexpensive hydraulically operated lift platform for a relatively smalltruck;

It is an additional object of the present invention to provide a liftplatform having a horizontal position movable in a vertical directionfor loading and unloading of goods into and from the truck, and alocked-inplace vertical stored position when the truck is in motion;

It is still a further object of the present invention to provide ahydraulically operated lift platform for a truck having a rear door suchthat the platform forms an integral part of the rear bumper when thetruck is in motion.

Lifts embodying the present invention include a first platform slidablymounted to vertical support structures on either. side of a loading doorof the van portion of a truck. Attached to the first platform is ahingedly mounted secondplatform which when in the loading position isparallel to the first platform in a generally horizontal plane and isvertically movable for loading and unloading of the truck. In theretracted position the second platform is approximately perpendicular tothe first platform and is locked in place. I-Iydraulically operatedcylinders are mounted on either side of the door opening and includelift rods coupled to either side of the first platform for raising andlowering the first and second platforms between the ground level and thetruck van floor level.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showingthe lift platform mounted to a van type of vehicle; the platform beinglowered to the ground level;

FIG. 2 is a perspective view showing the lift platform raised to aloading position level with the floor of the van and having metal racksresting upon it;

FIG. 3 is a perspective view showing the lift platform in its storedposition in which it is locked when the truck is in motion; and

FIG. 4 is a close-up view of the locking mechanism taken from inside thetruck van.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detailto the figures, there is shown a van body portion 10 of a truck whichincludes an access door 12 to allow packages and the like to be loadedon the floor area 14 inside the van body. The access door 12 is in thepreferred embodiment an overhead roll-up type of door (not shown) withan opening formed in the rear wall 16 of the van. Mounted to the wall 16on either side of the access door 12 is a pair of cylindrical supportmembers 20 and 22. The left support member 20 mounted to the left sideof the access door has one end bolted to an upper bracket 21 which is inturn bolted to the rear wall 16 of the van. The lower end of member 20is attached to a lower bracket 23 which is bolted or welded to thebumper portion 25 of the van. The right support bracket 22 is likewisebolted to the rear wall 16 of the van by means of an upper bracket 26and to the bumper portion 27 of the van by means of a lower bracket 28.Members 20 and 22 are generally parallel to one another and parallel tothe surface of the rear wall 16 of the truck. They extend verticallyfrom above the access door 12 down to the bumper sections 25 and 27.

Slidably mounted to the vertical support members 20 and 22 are guidemembers 30 and 32 between which a first platform 35 is welded at thelower end of the guide members. Members 30 and 32 comprise angle ironpieces which each include two sections of pipe 34 welded at a spacedinterval on each of the guide members. The pipe 34 has an inner diametergreater than the outer diameter of the cylindrical support members 20and 22. A nylon insert 36 is mounted between each of the pipe sections34 and the support members 20 and 22 (see FIG. 4). Thus, the firstplatform 35 is vertically movable by means of the guide members 30 and32 sliding on the support members 20 and 22, respectively.

I-Iingedly mounted to the first platform 35 is a second platform 65having a rear edge 67 mounted to the rear edge of the first platform 35by means of a piano-type hinge 68 shown in FIGS. 1 and 2. Platform 65includes left and righ edge members 72 and 74 and a beveled front lip 75which contacts the ground when the platform is lowered as shown inFIG. 1. The second platform 65 is supported by the hinge 68 and the topsurface of the first platform 35 when in the horizontal position asshown in FIG. 2 with a load mounted thereon. In one application the vanwas employed to -.make wholesale bakery goods deliveries. In thatapplication, the load 80 comprised a group of relatively heavy wirebaskets for holding baked goods.

A pair of hydraulic cylinders 46 and 48 are securely mounted to theupper portion of the support members 20 and 22 respectively by means ofbrackets 45. Each of the cylinders have lift rods (43 and 44 associatedwith cylinders 46 and 48 respectively) which are an integral part ofeach of the cylinders. The lift rods are coupled to the pistons includedin the cylinders (not shown) and move into or out of the cylinders asthe hydraulic pressure in the cylinder is changed. The verticallymovable lift rods are attached at one end to a bracket 42 on each guidemember 30 and 32. Thus as the lift rods move into or out of therespective cylinder the platforms 35 and 65 will be raised or lowered.

The hydraulic cylinders 46 and 48 are supplied hydraulic fluid by meansof hydraulic hoses 47 and 49 respectively (FIGS. 1 and 2) which arecoupled to a hydraulic pump and motor unit 50 mounted on the bumpersection 27 of the van 10. The unit 50 is actuated by means of a leverarm assembly 55 which includes a lever arm 56 slidably mounted by meansof brackets 57 and 58 to the rear wall 16 of the van 10. The lever arm46 is coupled to a combination switch and valve 51 on the unit 50 bymeans of a linkage arm 59 pivotaliy coupled to arm 56 by means of pivot52.

In the retracted position (FIG. 3) platform 65 is locked into place bymeans of a fork-shaped locking member 77 which is pivotally mounted tobracket 42 associated with the left guide member by means of a bolt 78(FIG. 4). The locking member 77 includes tines 81 and 83 which straddlethe front lip 75 of platform 65 as shown in FIG. 4 when in the lockedposition. The locking member 77 is held in position by means of a springloaded locking pin 79 (FIG. 4) having a T- shaped handle 85 (FIGS. 2 and3) and a spring loaded shaft portion which projects through bracket 42into an aperture 82 in member 77 (FIG. 4). To release the locking member77 (and platform 65) handle 85 is pulled out, thereby removing pin 79from aperture 82 such that member 77 can be swung upwardly and thesecond platform 65 can be pivoted about the hinge 68 to lower it to thehorizontal position shown in FIGS. 1 and 2. When in the retractedposition, the spring loaded locking pin 79 will prevent the lockingmembers 77 from pivoting and thereby hold the second platform 65 in anapproximate vertical position, as shown in FIGS. 3 and 4.

A safety chain 7 has one end securely attached to the van by means of abolt 88. The other end of chain 87 is removably hooked to platform 35 bya suitable hook (not shown) which is coupled to platform 35 when thetruck is in motion to insure that the lift will be held in its raisedposition in the event of a hydraulic fluid leak or valve failure.

OPERATION To utilize the lift platform from its retracted position shownin FIG. 3 it is necessary first to unhook the safety chain 87 from theplatform 35. Next the second platform 65 is lowered into its horizontalposition by pulling the T-handle 85 which releases latch 77, liftinglatch 77 and allowing the second platform 65 to be lowered to itshorizontal position where it is supported by the hinge 68 and firstplatform 35. The entire platform then can be lowered into the positionshown in FIG. 1 (i.e., ground level) by moving lever 56 downwardly tooperate the check valve in unit 51 such that the hydraulic pressure isreleased in the hydraulic cylinders 46 and 48. As this platform 65slowly lowers by sliding downwardly between the support members 20 and22 until it rests on the ground as shown in FIG. 1.

The packages 80 (FIG. 2) can then be placed on the platform 65 which israised by lifting the lever arm 56 which serves to actuate the electricmotor associated with the hydraulic pump unit 50 so that hydraulicpressure is applied to the cylinders by means of the hydraulic hoses 47and 49 coupled between the pump and the cylinders. As the fluid isforced into the cylinders the lift rods 43 and 44 raise thereby raisingplatform 65 and the packages 80 thereon up to the floor level of the van10 as shown in' FIG. 2. The packages 80 can then be easily slid onto thefloor 14 of the van. Platform 65 can then again be lifted into itsretracted position shown in FIG. 3. The locking mechanism 77 is thendropped over the forwardlip of the platform to lock it into place andthe safety chain 87 is coupled to platform 35. It is noted that thewidth of platform 65 can be somewhat less than the width of platform 35thereby allowing a step-through space on the right side of platform 65as shown in FIG. 3 such that the driver-deliveryman can gain access tothe inside of the van without the necessity of operating the platform.This facilitates the loading and unloading of relatively small packagesin which the use of the platform is not required. The motion of theplatform is controlled by the lever arm 56 which may be spring loadedsuch that it will return to its neutral position and such that it mustbe lifted to raise the platform by actuating the hydraulic pump, ordepressed downwardly to lower the platform by releasing the hydraulicpressure in the cylinders. This platform can be stopped at any positionbetween the two extreme levels by relieving the lever arm 56. Othercontrol arrangements could likewise be employed. The lift arm 56 mayinclude means for locking the arm into its neutral position such thatonly the driver with a key can operate the platform. The components ofthe lifting platform such as the support members, guide members,hydraulic cylinders, etc. are commercially available items which reducethe manufacturing costs of the lift since no specially manufacturedparts are required. In the preferred embodiment, the hydraulic cylinderswere 1 inch in diameter with a 42 inch travel and had a liftingcapability together of 3,000 pounds. Various modifications to thepreferred embodiment of the present invention will become apparent tothose skilled in the art and will fall within the scope of the presentinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

l. A lifting platform adapted to be mounted adjacent an access door of avan-type of truck comprising:

a first platform slidably mounted at either side thereof to a pair ofsupport members vertically mounted one on either side of said accessdoor;

a second platform having a width less than the ,width of said firstplatform and a length greater than twice the length of said firstplatform, said second platform hingedly mounted to one edge of saidfirst platform such that said second platform can be lowered into aposition overlaying said first platform to be solely supported therebyor raised to a position approximately perpendicular to said firstplatform;

a pair of hydraulic cylinders, one being mounted on either side of saidaccess door and rigidly mounted to said van portion of said truck, saidcylinders including lift rods mounted to said first platform;

a source of pressurized hydraulic fluid; and

means for selectively supplying said fluid to said hydraulic cylindersto lower and raise said first and second platforms between first andsecond positions.

2. A combined lifting platform and bumper adapted to be mounted adjacenta rear access door of a vantype of truck comprising:

first and second bumper segments mounted on opposite sides of the accessdoor of the truck;

a first platform slidably mounted at either side thereof to a pair ofsupport members vertically mounted one on either side of said accessdoor;

a second platform hingedly mounted to one edge of said first platformsuch that said second platform can be lowered into a position parallelwith said first platform or raised to a position approximatelyperpendicular to said first platform;

a pair of hydraulic cylinders, one being mounted on either side of saidaccess door and rigidly mounted to said van portion of said truck, saidcylinders including lift rods mounted to said first platform;

a source of pressurized hydraulic fluid; and

means for selectively supplying said fluid to said hydraulic cylindersto lower and raise said first and second platforms between first andsecond positions wherein said support members are positioned such thatsaid first platform is mounted between first and second bumper segmentsof said truck to form an integral part of the bumper when said first andsecond platforms are in said second position.

3. The mechanism of claim 1 wherein in said first position, said secondplatform is at ground level and in said second position said secondplatform is approximately level with a floor portion of said van.

4. The mechanism of claim 3 and further including locking means mountedto one of said support members for locking said second platform in saidapproximate vertical position.

5. A lifting mechanism as defined in claim 3 wherein said first andsecond platforms can be raised or lowered to any rest position betweensaid first and second positions.

6. The mechanism of claim 1 wherein said means for selectively supplyinghydraulic fluid to said hydraulic cylinders includes;

a hydraulic pump;

an electrical motor for actuating said pump;

control means for operating said motor,

a valve for relieving hydraulic pressure in said hydraulic cylinders;and

means for actuating said valve.

7. A mechanism of claim 6 and further including a safety chain havingone end mounted to said truck and another end removably mounted to saidfirst platform for holding said first platform at a preselected verticalposition.

8. A vertically movable lift platform mounted adjacent an access door ofa van-type truck, said platform comprising a first platform slidablymounted by guide brackets at either edge thereof to a pair of supportmembers vertically mounted adjacent said access door at either side ofsaid door, a pair of hydraulic cylinders rigidly. mounted to saidsupport members and including lift rods coupled to said guide members, asecond platform having a width less than the width of said firstplatform and a length at least twice the length of said first platform,said second platform hingedly mounted at one edge thereof to one edge ofsaid first platform such that said second platform can be rotated froman approximate vertical position to an approximate horizontal position,said second platform overlaying said first platform to be solelysupported thereby when in the approximate horizontal position, lockingmeans pivotally coupled to one of said guide means for holding saidsecond platform in said approximate vertical position when said lockingmeans are engaged, and means for selectively operating said hydrauliccylinders such that said first and second platforms can be raised andlowered.

9. The lift platform as defined in claim 3 wherein said means forselectively operating said hydraulic cylinders comprise: a source ofhydraulic fluid, a pump coupled to said source of fluid, an electricalmotor for actuating said pump, control means for operating said motor, acheck valve for relieving hydraulic pressure in said hydraulic cylinder,and means for actuating said check valve.

10. A vertically movable lift platform mounted adja cent an access doorof a vantype truck, said platform comprising a first platform slidablymounted by guide brackets at either edge thereof to a pair of supportmembers vertically mounted adjacent said access door at either side ofsaid door, a pair of hydraulic cylinders rigidly mounted to said supportmembers and including lift rods coupled to said guide members, a secondplatform hingedly mounted at one edge thereof to one edge of said firstplatform such that said second platform can be rotated from anapproximate vertical position to an approximate horizontal position,wherein the width of said second platform is less than the width of saidfirst platform thereby providing a space between said second platformwhen in said vertical position such that access can be gained to saidvan portion of said truck through said access door, locking meanspivotally coupled to one of said guide means for holding said secondplatform in said approximate vertical position when said locking meansare engaged, and means for selectively operating said hydrauliccylinders such that said first and second platforms can be raised andlowered, said means including a source of hydraulic fluid, a pumpcoupled to said source of fluid, an electrical motor for actuating saidpump, control means for operating said motor, a check valve forrelieving hydraulic pressure in said hydraulic cylinder, and means foractuating said check valve.

11. The mechanism as defined in claim 1 wherein the width of said secondplatform is selected to permit access to the door of the van adjacentwhich said mechanism is mounted when said second platform is in a raisedposition.

12. The mechanism as defined in claim 8 wherein the width of said secondplatform is selected to permit access to the door of the van adjacentwhich said mechanism is mounted when said second platform is in a raisedposition.

1. A lifting platform adapted to be mounted adjacent an access door of avan-type of truck comprising: a first platform slidably mounted ateither side thereof to a pair of support members vertically mounted oneon either side of said access door; a second platform having a widthless than the width of said first platform and a length greater thantwice the length of said first platform, said second platform hingedlymounted to one edge of said first platform such that said secondplatform can be lowered into a position overlaying said first platformto be solely supported thereby or raised to a position approximatelyperpendicular to said first platform; a pair of hydraulic cylinders, onebeing mounted on either side of said access door and rigidly mounted tosaid van portion of said truck, said cylinders including lift rodsmounted to said first platform; a source of pressurized hydraulic fluid;and means for selectively supplying said fluid to said hydrauliccylinders to lower and raise said first and second platforms betweenfirst and second positions.
 2. A combined lifting platform and bumperadapted to be mounted adjacent a rear access door of a van-type of truckcomprising: first and second bumper segments mounted on opposite sidesof the access door of the truck; a first platform slidably mounted ateither side thereof to a pair of support members vertically mounted oneon either side of said access door; a second platform hingedly mountedto one edge of said first platform such that said second platform can belowered into a position parallel with said first platform or raised to aposition approximately perpendicular to said first platform; a pair ofhydraulic cylinders, one being mounted on either side of said accessdoor and rigidly mounted to said van portion of said truck, saidcylinders including lift rods mounted to said first platform; a sourceof pressurized hydraulic fluid; and means for selectively supplying saidfluid to said hydRaulic cylinders to lower and raise said first andsecond platforms between first and second positions wherein said supportmembers are positioned such that said first platform is mounted betweenfirst and second bumper segments of said truck to form an integral partof the bumper when said first and second platforms are in said secondposition.
 3. The mechanism of claim 1 wherein in said first position,said second platform is at ground level and in said second position saidsecond platform is approximately level with a floor portion of said van.4. The mechanism of claim 3 and further including locking means mountedto one of said support members for locking said second platform in saidapproximate vertical position.
 5. A lifting mechanism as defined inclaim 3 wherein said first and second platforms can be raised or loweredto any rest position between said first and second positions.
 6. Themechanism of claim 1 wherein said means for selectively supplyinghydraulic fluid to said hydraulic cylinders includes; a hydraulic pump;an electrical motor for actuating said pump; control means for operatingsaid motor, a valve for relieving hydraulic pressure in said hydrauliccylinders; and means for actuating said valve.
 7. A mechanism of claim 6and further including a safety chain having one end mounted to saidtruck and another end removably mounted to said first platform forholding said first platform at a preselected vertical position.
 8. Avertically movable lift platform mounted adjacent an access door of avan-type truck, said platform comprising a first platform slidablymounted by guide brackets at either edge thereof to a pair of supportmembers vertically mounted adjacent said access door at either side ofsaid door, a pair of hydraulic cylinders rigidly mounted to said supportmembers and including lift rods coupled to said guide members, a secondplatform having a width less than the width of said first platform and alength at least twice the length of said first platform, said secondplatform hingedly mounted at one edge thereof to one edge of said firstplatform such that said second platform can be rotated from anapproximate vertical position to an approximate horizontal position,said second platform overlaying said first platform to be solelysupported thereby when in the approximate horizontal position, lockingmeans pivotally coupled to one of said guide means for holding saidsecond platform in said approximate vertical position when said lockingmeans are engaged, and means for selectively operating said hydrauliccylinders such that said first and second platforms can be raised andlowered.
 9. The lift platform as defined in claim 3 wherein said meansfor selectively operating said hydraulic cylinders comprise: a source ofhydraulic fluid, a pump coupled to said source of fluid, an electricalmotor for actuating said pump, control means for operating said motor, acheck valve for relieving hydraulic pressure in said hydraulic cylinder,and means for actuating said check valve.
 10. A vertically movable liftplatform mounted adjacent an access door of a vantype truck, saidplatform comprising a first platform slidably mounted by guide bracketsat either edge thereof to a pair of support members vertically mountedadjacent said access door at either side of said door, a pair ofhydraulic cylinders rigidly mounted to said support members andincluding lift rods coupled to said guide members, a second platformhingedly mounted at one edge thereof to one edge of said first platformsuch that said second platform can be rotated from an approximatevertical position to an approximate horizontal position, wherein thewidth of said second platform is less than the width of said firstplatform thereby providing a space between said second platform when insaid vertical position such that access can be gained to said vanportion of said truck through said access door, locking means pivotallycoupled to one of said guide means for holding said second platform insaid approximate vertical position when said locking means are engaged,and means for selectively operating said hydraulic cylinders such thatsaid first and second platforms can be raised and lowered, said meansincluding a source of hydraulic fluid, a pump coupled to said source offluid, an electrical motor for actuating said pump, control means foroperating said motor, a check valve for relieving hydraulic pressure insaid hydraulic cylinder, and means for actuating said check valve. 11.The mechanism as defined in claim 1 wherein the width of said secondplatform is selected to permit access to the door of the van adjacentwhich said mechanism is mounted when said second platform is in a raisedposition.
 12. The mechanism as defined in claim 8 wherein the width ofsaid second platform is selected to permit access to the door of the vanadjacent which said mechanism is mounted when said second platform is ina raised position.